1. Field of the Invention
The invention relates to a stylus, more particularly to a stylus device adapted for use with a capacitive touch panel.
2. Description of the Related Art
At present, touch-sense techniques have been widely applied to global positioning systems, personal digital assistants, cellular phones, palm-size computers and information appliances. Generally, touch-sense devices are of resistive, capacitive, surface acoustic wave sensitive, optic and electromagnetic. Particularly, a capacitive touch panel has been used in a handheld electronic device, such as a smart phone (e.g., an Apple iPhone) or a media player (e.g., an iPod Touch®).
The capacitive touch panel senses the position of a stylus that alters the transcapacitance coupling between row and column electrodes. For a capacitive touch panel, a user's finger can serve as a stylus in use. However, the user's finger may shield a part of an operating area of the capacitive touch panel. As a result, accurate position input cannot be obtained by means of the user's finger. Furthermore, a conventional stylus for a capacitive touch panel has a stylus tip with a certain touch area for touching the capacitive touch panel. However, the conventional stylus cannot accurately point to a position corresponding to a target pattern having an area smaller than the touch area.
Another conventional paintbrush stylus disclosed in U.S. Pat. No. 5,488,204 is used to produce paint-like strokes on a touch-sensor pad. However, such paintbrush stylus is relatively expensive and cannot prevent the aforesaid shielding problem during use. Therefore, accurate position input cannot be ensured.